Behind most caravan doors there are problems. Behind some, there are secrets. Behind one door there is ... murder. Joan's boredom as a fishing widow is swept away when Jack and his sticky beak wife Deirdre arrive at the caravan park. Jack has a crush on Joan, and when Melanie, a prostitute masquerading as a fashion saleswoman gets her hands on one of his love letters, she blackmails Joan. Troubles escalate when Joan discovers Trevor, the brooding husband of her friend Annabelle, in bed with Melanie. Sinister Vince, whose wheelchair bound mother hides some terrible secrets, is extracting large amounts of money from both Melanie and Trevor, and when Melanie is gruesomely murdered, he threatens to kill Joan if she reveals what she knows. Thinking she has played a major part in the murder because of terrible flashbacks, she confesses to killing Melanie ...and nothing is ever the same again.